234 [April 



[Mr. Loew's reply to my queries for information about Triogma ha* 

 come too late to be made use of in the text, otherwise it would probably 

 have influenced my views about the location of T. nodicornis. Mr. 

 Loew thinks that this species has either to be united to Cylindrotoma 

 , or to be constituted as a separate genus. He would prefer the former 

 course, because he possesses a Siberian species, Cylindrotoma nigri- 

 ventris, which has the thorax sculptured almost like T. nodicornis and 

 the antennal joints of which are somewhat expanded, thus likewise 

 approaching the latter species. Mr. Loew also adverts to the difference 

 in the general appearance, existing between T. nodicornis and T. trisul- 

 cata, the latter being shorter and stouter, and further points out some 

 other differences between them, in which T cannot fully concur. Mr. 

 Loew had but a very small number of specimens of T. nodicornis for 

 comparison and he was not aware of some characters, as for instance 

 the structure of the first antennal joint and the frequent absence of the 

 small transverse vein, which this species has in common with T. px- 

 sculpta and not with Cylindrotoma americana. Until I have an op- 

 portunity of seeing the European species of Cylindrotoma and Tiogma, 

 my opinion about the location of T. nodicornis will remain unsettled; 

 still, as a provisional arrangement, I would rather prefer the one adopted 

 by me.] 



B. Second group : Limnobina cylinprotom^eformia. 

 Gen. IX. CYLINDROTOMA. 



Characters. — First longitudinal vein incurved at the tip towards the second 

 and ending in it (and not in the costa) ; one exterior marginal, a submarginal. 

 a discal and four or Jive posterior cells. Anteiin.se 16-jointed, joints cylindrical, 

 very elongated. Eyes bare, separated by a rather broad interval above and be- 

 low the head. Tibiae with distinct spurs at the tip. Empodia distinct. For- 

 ceps of the male with claw-shaped horny appendages, which, in the state of 

 repose, are folded backwards, like the blade of a penknife, towards the upper 

 side of their basal pieces ; a long, narrow, linear lamella, deeply bidentate at 

 the tip, protrudes when the forceps is opened. 



Head rather broad posteriorly. 



Proboscis very short ; palpi somewhat elongated, last joint elongated ; 

 in C. americana it is about equal in length to the two preceding joints 

 taken together. 



Antennae rather long, joints elongated, almost cylindrical, finely pu- 

 bescent, with short, thin, rather scattered verticils. 



Collar e moderately developed. 



Thorax short, stout. 



Feet slender; spurs at the tip of the tibire of moderate length ; fore 

 coxae short; empodia distinct; excision at the basis of the last tarsal 



